Fix partial painting with render pipeline throttling

third_party/WebKit/Source/core/paint/FramePainter.cpp

Index: third_party/WebKit/Source/core/paint/FramePainter.cpp
diff --git a/third_party/WebKit/Source/core/paint/FramePainter.cpp b/third_party/WebKit/Source/core/paint/FramePainter.cpp
index 850393738b36dd5943d4be2aa3664223130e089b..a9a5461e108e9a65958f132b72505740cb0a6e55 100644
--- a/third_party/WebKit/Source/core/paint/FramePainter.cpp
+++ b/third_party/WebKit/Source/core/paint/FramePainter.cpp
@@ -91,8 +91,10 @@ void FramePainter::paintContents(GraphicsContext& context, const GlobalPaintFlag
         return;
     }
 
-    RELEASE_ASSERT(!frameView().needsLayout());
-    ASSERT(document->lifecycle().state() >= DocumentLifecycle::CompositingClean);
+    if (!frameView().shouldThrottleRendering()) {
+        RELEASE_ASSERT(!frameView().needsLayout());
+        ASSERT(document->lifecycle().state() >= DocumentLifecycle::CompositingClean);
+    }
 
     TRACE_EVENT1("devtools.timeline", "Paint", "data", InspectorPaintEvent::data(layoutView, LayoutRect(rect), 0));
 
@@ -115,7 +117,8 @@ void FramePainter::paintContents(GraphicsContext& context, const GlobalPaintFlag
     PaintLayer* rootLayer = layoutView->layer();
 
 #if ENABLE(ASSERT)
-    layoutView->assertSubtreeIsLaidOut();
+    if (!frameView().shouldThrottleRendering())
+        layoutView->assertSubtreeIsLaidOut();
     LayoutObject::SetLayoutNeededForbiddenScope forbidSetNeedsLayout(*rootLayer->layoutObject());
 #endif